This invention relates generally to the automotive arts and more particularly to an adjusting mechanism for an automobile headlamp assembly. Still more particularly, the invention relates to novel and improved gear box housing and retainer clip members for use in such an adjusting mechanism.
Mechanisms for vertical and horizontal adjustment or "aiming" of automobile headlamps have been provided for sealed beam-type automotive headlamps for some time. Generally speaking, such headlamps were individually adjustable with independent adjusting screws or the like, by driving the same with a suitable mating tool. Often, these adjusting screws were accessible only with some difficulty or upon removal of certain trim or bezel components of the headlamp assembly. Problems have been encountered in that these adjusting screws became corroded or otherwise fouled with rust and/or road grime, rendering the adjustment procedure time-consuming and difficult, or necessitating removal and replacement of a number of parts.
It has heretofore been proposed to utilize a novel type of adjusting mechanism which is mounted interiorly of the vehicle and which can be easily and readily operated to adjust vertical and/or horizontal positioning or "tilting" of the headlamps to achieve the desired aiming thereof. Such a mechanism would be independent of the headlamp members or other headlamp assemblies, such that it could be used with any of a wide variety of different headlamp shapes, sizes and configurations, interchangeably.
One such arrangement takes the form of a two-piece plastic "clam shell" type of housing which receives a pair of bevel or crown gear members arranged at right angles for engagement of gears along their respective edges so as to convert horizontal rotational motion to vertical rotational motion or vice versa. One of these gears is coupled to an elongate drive shaft member which may be coupled to suitable rotary drive means at its remote end. The other of the gears is coupled to an elongate threaded shaft member which is arranged to axially advance and retract a portion of the headlamp relative to the gear and housing in response to rotation of its associated gear. Accordingly, the rotary motion of the first or drive shaft is converted to generally linear or axial motion of the headlamp portion coupled to the second or adjusting shaft.
Another particularly novel and useful arrangement is a one-piece type of gear housing as shown in our prior U.S. application Ser. No. 794,092, filed Oct. 31, 1985 now abandoned and a continuation-in-part application, Ser. No. 851,331, filed Apr. 14, 1986 now U.S. Pat. No. 4,674,018. One of the objects of the novel one-piece gear housing arrangement in our above-referenced applications was to avoid a number of problems previously encountered with two-piece "clam shell" types of housings. In prior art two-piece or clam shell type housing arrangements, the gear members were often inadequately journaled, such that they would rattle and often fail to smoothly rotate and function properly. Moreover, the seam or parting line in the two-piece or clam shell type of housing often permitted the entry of moisture, road grime, grease and other contaminants which would tend to foul the operation of the gears over a period of time. Moreover, since the parting or joining line of the two-piece housing of necessity would define a plane which included the axis of at least one of the gears and its associated drive shaft or adjusting shaft member, any side loads occuring during operation of the members would tend to part or separate the housing halves or pieces. Such separation will of course further hamper proper journaling of the gears, the proper interengagement thereof for rotation and further aggravate the problem of access of moisture, grime, grease and other contaminants.
Yet other headlamp adjusting mechanisms have been proposed which are relatively complex and expensive. Examples of some of these latter mechanisms are shown in U.S. Pat. Nos. 4,271,456; 4,309,740 and 4,524,407.
The present invention is an improvement of the above prior art and in particular of the above two-piece or clam shell type of gear housing. In this regard the housing member of the invention is a two-piece clam shell type of member which is advantageously configured with additional means for maintaining the desired journaled condition of the gears in engagement with each other, with novel sealing means for avoiding the ingress of moisture, dirt, grease and the like, and with further additional strengthening members or means to resist parting or separating of the housing halves or parts in the presence of side loads during operation.
As an additional matter, many prior art gear box housings require a further retainer member or bracket, often in the form of a metal stamping for retaining at least one of the drive shaft and/or adjusting shaft members in the desired engaged condition with its associated gear member. However, use of this separate metal retaining clip gives rise to a number of additional problems. Initially, some of the dimensioning of the retaining clip was critical, in order to maintain the desired proper alignment of the adjusting and/or drive shaft member with its associated gear within the housing. This desired alignment often is difficult to achieve and maintain in practice with prior art types of brackets or retainer members.
Moreover, the provision of a separate retainer member provided an additional loose piece for assembly. That is, in relatively high volume, high speed automotive assembly lines, it is desirable to minimize the number of separate pieces which must be assembled. This is desired in order to optimize the assembly procedure and to avoid errors therein, such as misaligned or poorly assembled pieces, lost or missing pieces, or the like.
Finally, the metal retainer was often an expensive, brass or plated piece, thus further adding to the expense of the headlamp adjusting assembly. In high volume automotive assembly operations, an increase of even a few cents in the price of a given sub-assembly can add substantially to the overall cost of the operation and hence cost of the manufactured vehicles.
In accordance with another aspect of our invention, our novel and improved headlamp adjusting mechanism includes not only the clam shell gear housing discussed above, but also a novel and improved retainer member. Preferably, our retainer is molded as a one-piece integral member from a plastics material, and is engageable in a preassembled condition with the clam shell housing and ready to engage the adjusting or drive shaft to be retained thereby.